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BACKGROUND: Currently, spinal endoscopic technology has become the mainstream technology in minimally invasive spinal surgery. The specifications of the instruments for different operating systems are different, and the choice of specific surgical protocols needs to be combined with the actual situation of the patient and the choice of the clinical surgeon. OBJECTIVE: To compare the early efficacy of percutaneous endoscopic interlaminar discectomy for L5-S1 disc herniation under the iLESSYS Delta System and Endo-Surgi Plus System. METHODS: Totally 80 patients with L5-S1 disc herniation were treated with percutaneous endoscopic interlaminar discectomy. Patients were divided into two groups based on the endoscopic system used. Among them, 37 cases received the iLESSYS Delta System (Delta group) and 43 cases received the Endo-Surgi Plus System (Plus group). Patient demographic characteristics, perioperative indicators, and complications were analyzed between the two groups. Clinical outcomes were quantified using back and leg visual analog scale scores, Oswestry Disability Index, and Japanese Orthopaedic Association scores at 1 day, 1, 3, and 6 months after surgery. Patient satisfaction was assessed according to modified MacNab criteria at final follow-up. RESULTS AND CONCLUSION: (1) The operative time and number of arthroplasties in the Plus group were less than those in the Delta group, and the differences were statistically significant (P < 0.05). (2) Compared with the preoperative period, the visual analog scale scores, Oswestry Disability Index, and Japanese Orthopaedic Association scores of patients in both groups improved at all follow-up time points, and the difference was statistically significant (P < 0.001). (3) There was no statistically significant difference in the comparison of pain visual analog scale scores, Oswestry Disability Index, and Japanese Orthopaedic Association scores of patients in the two groups (P > 0.05). (4) At 6-month follow-up after surgery, the MacNab standard excellent and good rates in the Delta group and Plus group were 81% and 79%, respectively, with no significant difference (P=0.823). (5) The incidence of complications was 3% in the Delta group and 2% in the Plus group, but there was no significant difference between the two groups (P=0.914). (6) It is concluded that both iLESSYS Delta and Endo-Surgi Plus surgical systems achieved satisfactory early clinical results in the treatment of lumbar disc herniation, with Endo-Surgi Plus surgical moulding being more efficient and safer [ABSTRACT FROM AUTHOR]

Abstract Background Refractory chronic craniofacial pain is a debilitating condition with limited treatment options. This case report presents the use of percutaneous computed tomography-guided trigeminal tractotomy-nucleotomy under general anesthesia in a patient with refractory trigeminal neuralgia and post-treatment anesthesia dolorosa. This case report expands the use of TR-NC to include treatment-resistant post-treatment anesthesia dolorosa and introduces real-time verification under anesthesia, potentially broadening access and improving precision, while highlighting the need for further research on long-term efficacy and patient selection for this promising technique. Case presentation A 50-year-old woman with 12 years of chronic facial pain in the opthalmic and maxillary trigeminal branches despite multiple surgical and medical interventions underwent computed tomography-guided trigeminal tractotomy-nucleotomy under general anesthesia. Initial pain relief was significant, but symptoms gradually returned within 12 months. Transient mild ataxia was the only complication. Conclusion This case suggests trigeminal tractotomy-nucleotomy under general anesthesia with real-time verification may be a valuable option for patients with refractory post-treatment anesthesia dolorosa. However, the transient nature of pain relief necessitates further investigation of long-term outcomes and optimal patient selection.

Background: Refractory chronic craniofacial pain is a debilitating condition with limited treatment options. This case report presents the use of percutaneous computed tomography-guided trigeminal tractotomy-nucleotomy under general anesthesia in a patient with refractory trigeminal neuralgia and post-treatment anesthesia dolorosa. This case report expands the use of TR-NC to include treatment-resistant post-treatment anesthesia dolorosa and introduces real-time verification under anesthesia, potentially broadening access and improving precision, while highlighting the need for further research on long-term efficacy and patient selection for this promising technique. Case presentation: A 50-year-old woman with 12 years of chronic facial pain in the opthalmic and maxillary trigeminal branches despite multiple surgical and medical interventions underwent computed tomography-guided trigeminal tractotomy-nucleotomy under general anesthesia. Initial pain relief was significant, but symptoms gradually returned within 12 months. Transient mild ataxia was the only complication. Conclusion: This case suggests trigeminal tractotomy-nucleotomy under general anesthesia with real-time verification may be a valuable option for patients with refractory post-treatment anesthesia dolorosa. However, the transient nature of pain relief necessitates further investigation of long-term outcomes and optimal patient selection. [ABSTRACT FROM AUTHOR]

A modified phaco chop technique for nuclear emulsification in posterior polar cataracts with nuclear sclerosis that avoids hydrodissection or nuclear rotation has been described. After performing a vertical chop maneuver to divide the nucleus, two pie-shaped nuclear fragments are removed from either side of the initial chop. The remaining nuclear fragments are then sequentially tumbled toward the center using the second instrument and emulsified while maintaining an intact epinuclear shell, which safeguards the fragile posterior capsule. The technique was successfully performed in 62 eyes of 54 patients with posterior polar cataract and grade II–IV nuclear sclerosis. The Chop and Tumble nucleotomy is a safe and effective technique for phacoemulsification in posterior polar cataracts with nuclear sclerosis, where hydrodissection and nuclear rotation are typically avoided.

Purpose: The aim of this study was to elucidate segmental range of motion (ROM) before and after common decompression and fusion procedures on the lumbar spine. Methods: ROM of fourteen fresh-frozen human cadaver lumbar segments (L1/2: 4, L3/4: 5, L5/S1: 5) was evaluated in six loading directions: flexion/extension (FE), lateral bending (LB), lateral shear (LS), anterior shear (AS), axial rotation (AR), and axial compression/distraction (AC). ROM was tested with and without posterior instrumentation under the following conditions: 1) native 2) after unilateral laminotomy, 3) after midline decompression, and 4) after nucleotomy. Results: Median native ROM was FE 6.8°, LB 5.6°, and AR 1.7°, AS 1.8 mm, LS 1.4 mm, AC 0.3 mm. Unilateral laminotomy significantly increased ROM by 6% (FE), 3% (LB), 12% (AR), 11% (AS), and 8% (LS). Midline decompression significantly increased these numbers to 15%, 5%, 21%, 20%, and 19%, respectively. Nucleotomy further increased ROM in all directions, most substantially in AC of 153%. Pedicle screw fixation led to ROM decreases of 82% in FE, 72% in LB, 42% in AR, 31% in AS, and 17% in LS. In instrumented segments, decompression only irrelevantly affected ROM. Conclusions: The amount of posterior decompression significantly impacts ROM of the lumbar spine. The here performed biomechanical study allows creation of a simplified rule of thumb: Increases in segmental ROM of approximately 10%, 20%, and 50% can be expected after unilateral laminotomy, midline decompression, and nucleotomy, respectively. Instrumentation decreases ROM by approximately 80% in bending moments and accompanied decompression procedures only minorly destabilize the instrumentation construct. [ABSTRACT FROM AUTHOR]

A modified phaco chop technique for nuclear emulsification in posterior polar cataracts with nuclear sclerosis that avoids hydrodissection or nuclear rotation has been described. After performing a vertical chop maneuver to divide the nucleus, two pie-shaped nuclear fragments are removed from either side of the initial chop. The remaining nuclear fragments are then sequentially tumbled toward the center using the second instrument and emulsified while maintaining an intact epinuclear shell, which safeguards the fragile posterior capsule. The technique was successfully performed in 62 eyes of 54 patients with posterior polar cataract and grade II--IV nuclear sclerosis. The Chop and Tumble nucleotomy is a safe and effective technique for phacoemulsification in posterior polar cataracts with nuclear sclerosis, where hydrodissection and nuclear rotation are typically avoided. [ABSTRACT FROM AUTHOR]

Surgery of nucleus pulposus removal is one of the methods used for the treatment of lumbar disc herniation in the clinic. In order to understand the strain states of the lumbar intervertebral disc (IVD) after nucleotomy, the axial compression experiments of porcine lumbar IVD were implemented using digital image correlation (DIC) technology. The normal IVDs are named as control group; the IVDs treated with trypsin by removing the nucleus pulposus are named as experimental group. The distributions and the change rules of both axial and radial strains in different regions of the IVD with load were studied, and the experimental results of two groups were compared. The results show that both axial and radial strains of different regions increased with stress in two groups, and the variation had non-uniformity. The axial strain in the posterior region of the annulus fibrosus (AF) was larger than that in the anterior region, and the inner AF was larger than that of the outer AF. The axial strain increase of the experimental group was larger than that of the control group obviously. In the posterior region, the radial strain increase was larger than that in the anterior region, and the outer AF was significantly larger than that of the inner AF. The radial strain direction of the experimental group in the inner AF was towards the center of the nucleus pulposus, which was opposite to that of the control group, and the radial strain increase was evidently smaller than that of the control group. In the outer AF, the radial strain direction of the experimental group was the same as that of the control group and the radial strain increase was significantly larger than that. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the recurrence rate and the clinical outcomes (radicular pain, axial pain and muscle weakness) of patients undergoing sole sequestrectomy and compare them with a group treated by sequestrectomy with nucleotomy.And to verify the adequacy of the criterion used in this study to perform sequestrectomy alone. Method: Forty-eight consecutive patients 66 years of age or younger who had sequestered fragment/fragments that don't connect to nucleus pulpous and under the PLL, peridural or migrated caudally ostral in L2 - S1 levels presented in our clinic between 1/1/2018 – 1/1/2020.Patients included in this study had Fragment-Fissure herniations (characterized by disc herniation with a minimal annular defect and an extruded or sequestrated fragment) (carragee type 1).According to this criteria, we randomized equally the patients into group A (sequestrectomy without nucleotomy) [sequestrectomy wo/nucleotomy] and group B (sequestrectomy with nucleotomy) [sequestrectomy/w nucleotomy].4 patients were excluded from the study because they didn’t complete the follow-up questionnaire.Follow up of 21 months was available for the patients. A detailed analysis of the actual pain status, radicular and axial pain depending on VAS score, ODI, muscle weakness and recurrence were performed. Results: There was no statistically significant difference between the groups in terms of age, sex, comorbidities, radicular pain after surgery, muscle weakness, recurrence.ODI, The Oswestry Disability Index and axial pain postoperative were significantly lower and statically important in the sequestrectomy group.Our results clearly revealed postoperative differences in axial pain and ODI between two groups. Conclusion: Sequestrectomy alone is a safe operative modality. Patients have sequestered fragment with (Carragee type 1) findings maybe suitable to perform sequestrectomy alone because Sequestrectomy wo/nucleotomy does not seem to entail a higher rate of recurrences compared with sequestrectomy w/nucleotomy in this study and the results are as favorable as or better than results after sequestrectomy w/nucleotomy.More clinical studies are indeed to verify the adequacy of the criterion used in this study.

Painful herniated discs are treated surgically by removing extruded nucleus pulposus (NP) material (nucleotomy). NP removal through enzymatic digestion is also commonly performed to initiate degenerative changes to study potential biological repair strategies. Experimental and computational studies have shown a decrease in disc stiffness with nucleotomy under single loading modalities, such as compression-only or bending-only loading. However, studies that apply more physiologically relevant loading conditions, such as compression in combination with bending or torsion, have shown contradicting results. We used a previously validated bone-disc-bone finite element model (Control) to create a Nucleotomy model to evaluate the effect of dual loading conditions (compression with torsion or bending) on intradiscal deformations. While disc joint stiffness decreased with nucleotomy under single loading conditions, as commonly reported in the literature, dual loading resulted in an increase in bending stiffness. More specifically, dual loading resulted in a 40% increase in bending stiffness under flexion and extension and a 25% increase in stiffness under lateral bending. The increase in bending stiffness was due to an increase and shift in compressive stress, where peak stresses migrated from the NP-annulus interface to the outer annulus. In contrast, the decrease in torsional stiffness was due to greater fiber reorientation during compression. In general, large radial strains were observed with nucleotomy, suggesting an increased risk for delamination or degenerative remodeling. In conclusion, the effect of nucleotomy on disc mechanics depends on the type and complexity of applied loads. [ABSTRACT FROM AUTHOR]

• The influence of the intervertebral disc (IVD) nucleotomy on the load sharing in the spinal facet joint under the loading scenarios of different human postures was performed. • After the IVD nucleotomy, the forces in the facet joints are significantly increased under the postures of upright, 5° extension and 5° flexion. • The IVD nucleotomy can cause an increase in the overall forces in the facet joint and may serve as a possible explanation for the low back pain. One-in-five people suffer from chronic low back pain (LBP). The incidence of this disease has doubled since 1950s and affects not only the elderly, but also the young population. However, the mechanism of LBP is still unknown. A possible location where the LBP may develop is the facet joint and it has been revealed that the intervertebral disc (IVD) nucleotomy may be a trigger for LBP. The aim of the present study was to investigate the influence of IVD nucleotomy on the load sharing in the spinal facet joint under the loading scenarios of different postures. Finite element (FE) models of the intact and nucleotomised L4 – L5 spinal segments were generated from the clinical CT images. Seven human postures, including upright, 5° extension, 5° flexion, ± 6° lateral bending and ± 2° axial rotation, were simulated. The resultant forces in the fact joint were compared between the intact and the nucleotomised cases. It was revealed that the IVD nucleotomy significantly increased the forces in the facet joints under the loading scenarios of upright, 5° extension and 5° flexion. The IVD nucleotomy increased the force in the ipsilateral facet joint but decreased the force on the contralateral side under the loading scenarios of ± 2° axial rotation. However, the IVD nucleotomy made little influence on the resultant forces in both facet joints in the postures of ± 6° lateral bending. In conclusion, the IVD nucleotomy can cause an increase in the overall force in the facet joint, and thus may serve as a possible explanation for the LBP and a main contributing factor for the pain complaints. [ABSTRACT FROM AUTHOR]

Nucleotomy is a common surgical procedure for the treatment of lumbar diseases. It may accelerate degeneration in the operated disc and decreased segmental stability, and this has been widely concerned by scholars for many years. However, under whole-body vibration, nucleotomy how to affect the vibration characteristics of the lumbar spine and complications is urgent to know. A three-dimensional nonlinear osteoligamentous finite element model of the intact L1-sacrum lumbar spine with muscles was established, and the nucleus of the L4–L5 disc was removed in the nucleotomy model. The lower surface of the sacrum was fully constrained for all models. A 5 Hz, 40 N sinusoidal vertical load supplemented with a 400 N preload was applied at L1 to simulate the vertical vibration of the human body. The results showed that nucleotomy increased the dynamic responses of the discs such as stress in the annulus ground substance and intradiscal pressure both in the maximum value and vibration amplitude. The maximum endplate stresses and corresponding vibration amplitudes of the denucleated L4–L5 level increased because of nucleotomy. Nucleotomy decreased the maximum response values of disc height and segmental lordosis but increased the corresponding amplitudes. Therefore, these findings imply that nucleotomy may increase the risk of developing complications such as disc degeneration, adjacent segment disease, endplate degeneration, lumbar instability, nerve root compress, isthmic spondylolisthesis, and lumbar disc herniation under whole-body vibration. This study reveals insights into the effect of the nucleotomy on the vibration characteristics of the lumbar spine and provides new information toward the relationship between nucleotomy and complications. [ABSTRACT FROM AUTHOR]

Finite element (FE) models can unravel the link between intervertebral disc (IVD) degeneration and its mechanical behaviour. Nucleotomy may provide the data required for model verification. Three human IVDs were scanned with MRI and tested in multiple loading scenarios, prior and post nucleotomy. The resulting data was used to generate, calibrate, and verify the FE models. Nucleotomy increased the experimental range of motion by 26%, a result reproduced by the FE simulation within a 5% error. This work demonstrates the ability of FE models to reproduce the mechanical compliance of human IVDs prior and post nucleotomy. [ABSTRACT FROM AUTHOR]

Purpose: Disc herniations are usually treated by decompression of the spinal nerves via a partial nucleotomy. As a consequence of reduced disc height (DH), reduced intradiscal pressure (IDP) and increased range of motion (ROM), accelerated degeneration may occur. Nucleus replacement implants are intended to restore those values, but are associated with the risk of extrusion.Methods: In six fresh frozen lumbar spinal segments (L2-3/L3-4/L4-5/L5-S1, age median 64.5 years (57-72), Pfirrmann grade 2-3), a prolapse was provoked through a box defect (6 × 10 mm) in the annulus. The herniated nucleus material was removed and replaced by a novel collagen-based nucleus implant. An annulus closure device sealed the defect. ROM, neutral zone (NZ) and IDP were measured in the (1) intact and (2) defect state, (3) postoperatively and (4) after cyclic loading (n = 100,000 cycles) applying pure moments (± 7.5 Nm) in flexion-extension, lateral bending and axial rotation. Additionally, the change in DH was determined. Extrusion of implants or nucleus material was evaluated macroscopically.Results: In all specimens, a prolapse could be provoked which decreased DH. Subsequent nucleotomy changed ROM/NZ and IDP considerably. Initial values could be restored by the implantation. Macroscopically, none of the implants nor nucleus material did migrate after cyclic loading.Conclusions: In this study, a prolapse followed by a nucleotomy resulted in a biomechanical destabilisation. Implantation of the nucleus replacement combined with an annulus closure restored the intact condition without showing signs of extrusion nor migration after cyclic loading. Hence, nucleus replacements could have a new chance in combination with annulus closure devices. [ABSTRACT FROM AUTHOR]

In vitro and in vivo studies evidenced that mesenchymal stem cells (MSCs) contribute to intervertebral disc (IVD) regeneration by differentiation towards the disc phenotype and matrix synthesis and/or by paracrine signalling to endogenous cells, thereby promoting a healthier disc phenotype in degenerative discs. The aim of this study was to investigate IVD response to human MSC (hMSC) treatment based on the disc degenerative state and hMSC carrier. Bovine caudal IVDs with endplates were cultured in a bioreactor under simulated physiological (0.1 Hz load and sufficient glucose) or degenerative (10 Hz load and limited glucose) conditions for 7 days. Discs were partially nucleotomised, restored with hMSCs in either fibrin gel or saline solution and cultured under physiological conditions for 7 days. Controls included fibrin and saline without hMSCs. Cell viability, histology, disc height, and gene expression analyses were performed to evaluate regeneration. hMSCs in fibrin were viable and homogenously distributed following 7 days of culture under dynamic loading in partially nucleotomised discs. IVD response to hMSCs was conditioned by both disc degenerative state and hMSC carrier. The effect of the regenerative treatment was stronger on simulated-degenerative discs than on simulated-physiological discs. hMSCs in fibrin induced a superior anabolic response in degenerative IVDs compared with fibrin alone, thus suggesting an added value of the cellular therapy compared with an acellular solution. When comparing fibrin and saline as a hMSC carrier, a significantly higher anabolic response was observed in IVDs treated with hMSCs in fibrin. Moreover, it was found that the degenerative state of the disc influenced hMSC differentiation. Indeed, a significantly higher expression of specific discogenic markers (ACAN and CA12) was observed in hMSCs implanted into physiological discs than in those implanted into degenerative discs. In conclusion, host disc cells and donor hMSC response depend on the degenerative state of the host disc and carrier used for hMSC delivery, and these two aspects need to be considered for a successful translation of hMSC therapies for the treatment of IVD degeneration.

Nucleotomy is the gold standard treatment for disc herniation and has proven ability to restore stability by creating a bony bridge without any additional fixation. However, the evolution of mineral density in the extant and new bone after nucleotomy and fixation techniques has to date not been investigated in detail. The main goal of this study is to determine possible mechanisms that may trigger the bone remodelling and formation processes. With that purpose, a finite element model of the L4–L5 spinal segment was used. Bone mineral density (BMD), new tissue composition, and endplate deflection were determined as indicators of lumbar fusion. A bone-remodelling algorithm and a tissue-healing algorithm, both mechanically driven, were implemented to predict vertebral bone alterations and fusion patterns after nucleotomy, internal fixation, and anterior plate placement. When considering an intact disc height, neither nucleotomy nor internal fixation were able to provide the necessary stability to promote bony fusion. However, when 75% of the disc height was considered, bone fusion was predicted for both techniques. By contrast, an anterior plate allowed bone fusion at all disc heights. A 50% disc-height reduction led to osteophyte formation in all cases. Changes in the intervertebral disc tissue caused BMD alterations in the endplates. From this observations it can be drawn that fusion may be self-induced by controlling the mechanical stabilisation without the need of additional fixation. The amount of tissue to be removed to achieve this stabilisation remains to be determined. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of transforaminal lumbar interbody fusion (TLIF) with bilateral pedicle screw fixation (BPSF) on dynamic responses of the adjacent spinal segments to whole body vibration (WBV) after nucleotomy. A previously validated finite element model of an intact L1-sacrum lumbar spine was modified to simulate nucleotomy with and without TLIF and BPSF at L4-L5. Transit dynamic analyses were conducted on the nucleotomy alone and the fusion models under a vertical vibration load. The computed dynamic responses for the two models at adjacent levels were recorded and compared. The results showed that at level (L5-S1) below the denucleated disc, maximum response values of the disc bulge, annulus stress and intradiscal pressure decreased due to the fusion by 5.6%, 5.2% and 7.2%, and their vibration amplitudes decreased by 30.5%, 25.7% and 24.3%. At levels (L1-L2, L2-L3 and L3-L4) above the denucleated disc, maximum response values and vibration amplitudes of the strains and stresses also produced 5.2-8.9% and 25.9-29.7% deceases due to the fusion. It implies that after nucleotomy, application of the TLIF with BPSF might be helpful to prevent negative effects of the vertical WBV on adjacent disc levels. [ABSTRACT FROM AUTHOR]

BACKGROUND: Spinal surgeries have strongly increased in number over the past decade. The question of when it is safe to resume driving is thereby one the most frequently asked questions that patients ask of their treating physician. OBJECTIVE: The aim of this study was to assess braking performance before and after spine surgery. METHODS: Reaction time, foot transfer time (together brake response time [BRT]), and brake force (BF) were evaluated in a drive simulator. A longitudinal patient cohort (n = 27) was tested preoperatively and at the first follow-up. A cross-sectional cohort (n = 27) was tested at > 1 year postoperatively. The values from these groups were compared with a healthy age-matched control group of 24 volunteers. RESULTS: No significant improvement in BRT was seen in lumbar fusion three months postoperatively (p = 0.597); BF was even weaker than it was preoperatively (p = 0.044). In comparison to the control group (median BRT 479 ms), preoperative BRT was already impaired in lumbar fusion patients (median 560 ms), representing an increased braking distance of 2.25 m at 100 km/h. CONCLUSION: Although most patients performed adequately, about one third presented critical braking performance. Risk factors for impaired braking may include scheduled multisegmental fusion surgery, female sex, and pain. [ABSTRACT FROM AUTHOR]

Background:clinical outcome data was analyzed for 100 patients withcontained disc herniation who underwent percutaneous discdecompression procedure using Coblation® technology,after failing to respond toconservative management. Patients and Methods: Patients presented with clinicalsymptoms of discogenic low back pain and/or leg painFollow-up data was collected up to 12 months.Patient gender distribution was 68% female, 32% male, witha mean age of 39 years.With mean duration of back pain of 8.57 ,ranging from 3 to 17 month and mean duration of leg pain of 4.36 .ranging from 2 to 10 monthaccording to visual analogue scale for pain assessment.The mean pre-procedure pain level for all patients wasReported as 7.56 for back and 7.72 for leg while average pain level was 4.86 for back and 3.42 for leg at the 12-month follow-up post procedure period. And according to Oswestry disability index for functional assessment. The mean pre procedure index was 31.48 range from 23-40. It decreased after 12 month to 13.82 range from 5-32. Results:The results of this analysis indicated that PDD usingCoblation technology, isan effective procedure for patients presenting withdiscogenic back and/or leg pain who have failed conservativetherapies. [ABSTRACT FROM AUTHOR]

Background The number and cost of instrumented spinal fusion surgeries have increased rapidly, primarily for the treatment of lumbar segmental instabilities. However, what if the organism itself is able to restore segmental stability over time? This large-animal study using sheep aimed to investigate whether the reparative response after destabilization via facetectomy and nucleotomy without instrumentation can effectively fuse the spinal segment comparable to instrumented standard fusion surgery. Methods The following four surgical interventions were investigated: dorsal fixation via internal fixator, ventral fixation via cage as well as facetectomy and nucleotomy without additional instrumentation. Six months postoperatively, the animals were sacrificed, and the lumbar spines were used for biomechanical tests. Findings Spinal stability was restored to the destabilized spinal segments at six months postoperatively and was comparable to the results of conventional surgery via screws and cages. Iatrogenic hypomobilization caused significant reductions in facet joint space and intervertebral disc height of segments at index and adjacent level. Restabilized segments after iatrogenic hypermobilzation also significantly decreased facet joint space and disc height at index level, but revealed no influence on adjacent segments. Interpretation These findings in the sheep model question the necessity of costly instrumentation and suggest the alternative possibility of stimulating the reparative capacity of the body in human lumbar spine fusion surgery. [ABSTRACT FROM AUTHOR]

Removal of herniated disc materials based on an imaging only method may not relieve symptoms in many patients. Therefore, the aim of the present study was to develop a transforaminal endoscopic method of classifying the pathological type of lumber intervertebral disc herniation and to compare the outcomes of surgery based on the pathological type with those of conventional endoscopic disc removal. The records of patients who received endoscopic transforaminal nucleotomy with foraminoplasty for symptomatic lumbar disc herniation between 2009 and 2013 were retrospectively reviewed. Patients were then divided into two groups: Group A, which consisted of 275 patients who received conventional endoscopic transforaminal nucleotomy with foraminoplasty between 2009 and 2011 and group B, which consisted of 316 patients who received 'targeted' endoscopic transforaminal nucleotomy with foraminoplasty between 2011 and 2013 (based on the pathological type of disc herniation identified at surgery, including fresh, calcified and scar type based on intraoperative observations). The results showed that there were no significant differences in age, gender, body mass index, symptom duration, operated segments or previous invasive therapies between the two groups. Moreover, evaluation of visual analogue scale pain scores and Oswestry disability index scores revealed that the patients in group B had a greater improvement in symptoms than those in group A (P<0.05). In addition, an age >40 years and a longer symptom duration were associated with the calcified type, and previous invasive therapy was associated with the scar type. Therefore, specific surgical treatment based on the transforaminal endoscopic pathological type can result in better outcomes for patients with lumbar disc herniation. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to establish a large animal model that recapitulates the spectrum of intervertebral disc degeneration that occurs in humans and which is suitable for pre-clinical evaluation of a wide range of experimental therapeutics.Design: Degeneration was induced in the lumbar intervertebral discs of large frame goats by either intradiscal injection of chondroitinase ABC (ChABC) over a range of dosages (0.1U, 1U or 5U) or subtotal nucleotomy. Radiographs were used to assess disc height changes over 12 weeks. Degenerative changes to the discs and endplates were assessed via magnetic resonance imaging (MRI), semi-quantitative histological grading, microcomputed tomography (μCT), and measurement of disc biomechanical properties.Results: Degenerative changes were observed for all interventions that ranged from mild (0.1U ChABC) to moderate (1U ChABC and nucleotomy) to severe (5U ChABC). All groups showed progressive reductions in disc height over 12 weeks. Histological scores were significantly increased in the 1U and 5U ChABC groups. Reductions in T2 and T1ρ, and increased Pfirrmann grade were observed on MRI. Resorption and remodeling of the cortical boney endplate adjacent to ChABC-injected discs also occurred. Spine segment range of motion (ROM) was greater and compressive modulus was lower in 1U ChABC and nucleotomy discs compared to intact.Conclusions: A large animal model of disc degeneration was established that recapitulates the spectrum of structural, compositional and biomechanical features of human disc degeneration. This model may serve as a robust platform for evaluating the efficacy of therapeutics targeted towards varying degrees of disc degeneration. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare two approaches for the delivery of biomaterials to partially nucleotomised intervertebral discs in whole organ culture under loading. Such models can help to bridge the gap between in vitro and in vivo studies by assessing (1) suitability of biomaterial delivery and defect closure methods, (2) effect of mechanical loading and (3) tissue response.Methods: Mechanical performance of bovine discs filled with a hyaluronan-based thermoreversible hydrogel delivered through the annulus fibrosus (AF) or the bony endplate (EP) was evaluated under cyclic axial loading in a bioreactor. The loading protocol was optimised to achieve physiological disc height changes in nucleotomised discs. A loading regime of 0.06 ± 0.02 MPa, 0.1 Hz, 6 h daily was applied on the nucleotomised discs. Disc height and stiffness were tracked for 5 days, followed by histological analyses.Results: Creation of a defect is less demanding for AF approach, while sealing is superior with the EP approach. Dynamic compressive stiffness is reduced following nucleotomy, with no significant difference between the two approaches. Disc height loss was higher, disc height recovery was lower and region around the defect with reduced cell viability was smaller for AF-approached than EP-approached discs.Conclusions: Two alternative methods for biomaterial testing in whole organ culture under loading were developed. Such models bring insights on the ability of the biomaterial to restore the mechanical behaviour of the discs. From a clinical perspective, the cavity models can simulate treatment of nucleotomy after disc herniation in young patients, whereby the remaining nucleus pulposus is still functional and therefore at high risk of re-herniation, though the defect may differ from the clinical situation. [ABSTRACT FROM AUTHOR]

Different minimally invasive procedures are used to treat lumbar disk herniation. It is important to differentiate these techniques due to their specific effects and the disparate technical issues associated with each. This report describes a successful case involving the use of mechanical decompression in conjunction with radiofrequency ablation to treat a patient with pain and neurological deficits due to an extruded disk hernia. Case Report A 43-year-old male had magnetic resonance imaging (MRI) demonstrating an extruded disk herniation in the left foraminal region, compression at the left spinal nerve root, and obliteration of the left foraminal entrance of the L5-S1 distribution. In the operating room, sufficient disk material was removed using grasping forceps, and then, the Disc-FX system with a Trigger-Flex probe (Elliquence, Baldwin, NY, U.S.A.) was inserted. Modulation of the annulus was performed in bipolar hemo mode, and nucleus ablation was conducted in bipolar turbo mode within a 1.7-MHz frequency range. Among the available minimally invasive techniques, newly developed technologies may become important treatment options if they enable faster rehabilitation, lower rates of recurrence, shorter hospital stays, and reduced medical costs. [ABSTRACT FROM AUTHOR]

Laser discectomy or nucleotomy is an increasingly important method for less invasive procedures of column, but the ideal kind of laser is still not established. As the wavelength is an important parameter for water absorption, this study was performed to investigate the action of the laser emission in the near infrared (808 to 1908 nm) region in the context of surgical procedures for percutaneous intervertebral disc decompression (nucleotomy). Forty intervertebral discs from pigs lumbar spines were irradiated with laser (λ = 808, 980, 1470 and 1908 nm), 1-s on/off time cycles, for 120 cycles and 10 W of power (808, 980, and 1470 nm) or 240 cycles and 5 W of power (1908 nm), with total power of 1200 J, and subjected to microscopic evaluation through hematoxylin-eosin (HE) staining in order to measure the ablation lesions and the residual thermal injury. Ten other discs were not irradiated and worked as controls. The ablation lesions were measured (in mm) at 1.08 ± 1.25, 1.70 ± 0.63, 2.23 ± 1.02, 1.37 ± 0.39, and 0.94 ± 0.41 (median ± SD) for the control, 808, 980, 1470, and 1908 nm groups, respectively. The difference between 1908 nm and all the other groups was statistically significant (p < 0.05). The residual thermal injury was less evident in 1908 nm laser and sharper in 980 nm laser wavelengths. The laser at a wavelength of 1908 nm was considered the most efficient for the vaporization of the nucleus pulposus, followed by the laser wavelengths of 1470, 808, and 980 nm, and proved to be useful for laser nucleotomy procedure. [ABSTRACT FROM AUTHOR]

Nucleus pulposus (NP) replacement offers a minimally invasive alternative to spinal fusion or total disc replacement for the treatment of intervertebral disc (IVD) degeneration. This study aimed to develop a cytocompatible NP replacement material, which is feasible for non-invasive delivery and tunable design, and allows immediate mechanical restoration of the IVD. A bi-phasic polyurethane scaffold was fabricated consisting of a core material with rapid swelling property and a flexible electrospun envelope. The scaffold was assessed in a bovine whole IVD organ culture model under dynamic load for 14 days. Nucleotomy was achieved by incision through the endplate without damaging the annulus fibrosus. After implantation of the scaffold and in situ swelling, the dynamic compressive stiffness and disc height were restored immediately. The scaffold also showed favorable cytocompatibility for native disc cells. Implantation of the scaffold in a partially nucleotomized IVD down-regulated catabolic gene expression, increased proteoglycan and type II collagen intensity and decreased type I collagen intensity in remaining NP tissue, indicating potential to retard degeneration and preserve the IVD cell phenotype. The scaffold can be delivered in a minimally invasive manner, and the geometry of the scaffold post-hydration is tunable by adjusting the core material, which allows individualized design. [ABSTRACT FROM AUTHOR]

Background: Less invasive treatment methods for intervertebral disc disease and decompression of neural structures as a consequence of contained disc herniation represent an alternative to surgical procedure. Percutaneus nucleotomy uses a percutaneous approach to the intervertebral disc. The article presents the evolution of numerous procedureds in clinical practice.Methods: Percutaneous nucleoplasty is a fluoroscopy-guided procedure which enables controlled and safe entrance into the intervertebral disc. The procedure is performed under strict aseptic conditions, using a local anaesthesia with the patient under analgosedation. Based on the principle of therapeutic intradiscal action, the procedures can be divided into three groups: chemical (chemonucleolysis with chimopapain, alcohol, ozone), mechanical (automated percutaneous lumbar discectomy – APLD, arthroscopic discectomy) and thermical methods (laser, radiofrequency ablation, intradiscal electrothermal annuloplasty – IDET, Coblation®).Results: Percutaneous nucleotomy by the majority of the mentioned procedures results in a therapeutic effect (reduction of pain and decompression of neural structures). Fast recovery represents a major advantage of less invasive treatment.Conclusions: Less invasive method (nucleotomy using different procedures) represents a successful alternative approach to surgical discectomy. Proper patient selection and safe technique are mandatory in order to achieve a good clinical outcome.

The first objective of this study was to determine the effects of physiological cyclic loading followed by unloaded recovery on the mechanical response of human intervertebral discs. The second objective was to examine how nucleotomy alters the disc's mechanical response to cyclic loading. To complete these objectives, 15 human L5-S1 discs were tested while intact and subsequent to nucleotomy. The testing consisted of 10,000 cycles of physiological compressive loads followed by unloaded hydrated recovery. Cyclic loading increased compression modulus (3%) and strain (33%), decreased neutral zone modulus (52%), and increased neutral zone strain (31%). Degeneration was not correlated with the effect of cyclic loading in intact discs, but was correlated with cyclic loading effects after nucleotomy, with more degenerate samples experiencing greater increases in both compressive and neutral zone strain following cyclic loading. Partial removal of the nucleus pulposus decreased the compression and neutral zone modulus while increasing strain. These changes correspond to hypermobility, which will alter overall spinal mechanics and may impact low back pain via altered motion throughout the spinal column. Nucleotomy also reduced the effects of cyclic loading on mechanical properties, likely due to altered fluid flow, which may impact cellular mechanotransduction and transport of disc nutrients and waste. Degeneration was not correlated with the acute changes of nucleotomy. Results of this study provide an ideal protocol and control data for evaluating the effectiveness of a mechanically-based disc degeneration treatment, such as a nucleus replacement. [ABSTRACT FROM AUTHOR]

Low-back pain has been related to degenerative changes after nucleotomy. Although several etiologies for pain after nucleotomy have been proposed, there is evidence of pain arising in the facet joints in general, which may be related to changes in load transfer. This study addresses the effect of nucleotomy on facet joint loading. Nine human lumbar motion segments (age: 40-59 years) were loaded in axial compression and extension-flexion. Reaction forces were compared with soft tissue structures sequentially removed. After nucleotomy the facets supported significantly greater load, almost doubling from a median of 8.6% of the applied external force to 15.8%. Force transmission related to the capsular ligament increased significantly from an intact median of 1.2-5.1% after nucleotomy. No correlation was observed between force increase on the facets and the proportion of disc nucleus removed. Even a small quantity of nucleus removal (range: 0.7-1.7 g) increased the forces transmitted over the facet joints, both with and without capsular ligaments. This suggests that the proportion of material removed might not be important clinically with regard to facet joint degeneration and pain. [ABSTRACT FROM AUTHOR]

Objective: When used to treat craniofacial pain, CT-guided trigeminal tractotomy-nucleotomy (TR-NC) is usually performed with local anesthesia. Unfortunately, local anesthesia is insufficient for patients with such severe pain that they cannot tolerate the required head positioning while awake. This study aimed to contextualize previous findings associated with TR-NC performed under general anesthesia. The authors examined clinical and operative factors that could impact postoperative pain outcomes., Methods: This is a retrospective single-institution cohort study of patients who underwent a percutaneous CT-guided TR-NC under general anesthesia at a single institution between 2012 and 2019. Outcome data were analyzed., Results: Twenty-five patients underwent CT-guided TR-NC procedures under general anesthesia; 23 met the inclusion criteria and underwent a total of 31 procedures. The procedure success rate was 74% (23/31). Approximately 50% and 40% of procedures provided pain relief for at least 6 and 12 months, respectively. The median duration of pain relief was 153 days. Adverse events, all minor and transient, occurred following 6/31 (19%) of procedures. Patients with a body mass index > 25 were less likely to experience a successful TR-NC (p = 0.045). Higher electrode ablation temperatures (p = 0.033) and more medial entry trajectories relative to the midsagittal plane (p = 0.029) characterized successful procedures., Conclusions: These results suggest that CT-guided TR-NC performed under general anesthesia is safe and effective. Postoperative outcomes were found to be associated with a number of clinical and operative factors. Such associations should be further explored and evaluated in the context of future, better-powered analyses.